1. Field of the Invention
This invention relates to a backing and alignment ring assembly for insertion in pipes, more particularly for alignment of abutting pipe ends for welding.
2. Description of the Prior Art
When pipes are to be welded together, it is desirable that their abutting ends should be as accurately aligned as possible. Known externally mounted means of alignment may interfere with accessibility to the joint to be welded if disposed too near the joint, and are therefore unsuitable for providing rigid alignment close to the joint.
At the same time, there is a requirement in certain forms of welding for a backing piece on the opposite side of the metal to that on which the weld is being applied, which acts as a heat sink and controls the flow of weld metal.